Answer :
Answer:
D) consume more of Good X or less of Good Y until the marginal utility per dollar for Good X and Good Y is equal.
Explanation:
Since Joanna's marginal utility per dollar is higher for good X than per good Y, then she must consume a combination of both goods until their marginal utility per dollar is equal.
Since marginal utility is diminishing, if she reduces her consumption of good Y, maybe it will increase and match X's. Or she can choose to consume more X until its marginal utility diminishes and matches Y's.